Sino-French War in the context of Amédée Courbet

Keelung (/kiːˈlʊŋ/ kee-LUUNG; Chinese: 基隆; pinyin: Jīlóng; Pe̍h-ōe-jī: Ke-lâng), Chilung or Jilong (/dʒiːˈlʊŋ/ jee-LUUNG), officially known as Keelung City, is a major port city in northeastern Taiwan. The city is part of the Taipei–Keelung metropolitan area with neighboring New Taipei City and Taipei. Nicknamed the Rainy Port for its frequent rain and maritime role, the city is Taiwan's second largest seaport (after Kaohsiung), and was the world's 7th largest port in 1984.

In 1626, the Spanish established Fort San Salvador at present-day Keelung, an area inhabited by Taiwanese indigenous peoples. Control of the area eventually passed to the Qing dynasty. Fighting between China and Europeans around Keelung occurred in the 19th century during the First Opium War and the Sino-French War. The island of Taiwan was ceded to the Empire of Japan in 1895 after the First Sino-Japanese War; under Japanese rule the city was called Kirun. Keelung became part of Taiwan Province under the Republic of China after 1945. Administratively, the city became a first-level subdivision in 2018 after the provincial government was abolished.

The Guangxu Emperor (14 August 1871 – 14 November 1908), also known by his temple name Emperor Dezong of Qing, personal name Zaitian, was the tenth emperor of the Qing dynasty, and the ninth Qing emperor to rule over China proper. His succession was endorsed by dowager empresses Ci'an and Cixi for political reasons after the Tongzhi Emperor died without an heir. Cixi held political power for much of Guangxu's reign as regent, except for the period between his assumption of ruling powers in 1889 and the Hundred Days' Reform in 1898.

The Qing Empire's prestige and sovereignty continued to erode during Guangxu's reign with defeats in the Sino-French War, the First Sino-Japanese War, and the Boxer Rebellion. Guangxu engaged intellectuals like Kang Youwei and Liang Qichao to develop the Hundred Days' Reform program of 1898 to reverse the decline. Among the goals was removing Cixi from power. The program was too radical for the conservative ruling elite, and it failed to secure the support of the army. Cixi rallied the program's opponents to launch a coup in late 1898 that suppressed the reforms and secured her power. Guangxu lost ruling powers and was placed under virtual house arrest at the Yingtai Pavilion of Zhongnanhai until his death.

The Tonkin campaign was an armed conflict fought between June 1883 and April 1886 by the French against, variously, the Vietnamese, Liu Yongfu's Black Flag Army and the Chinese Guangxi and Yunnan armies to occupy Tonkin (northern Vietnam) and entrench a French protectorate there. The campaign, complicated in August 1884 by the outbreak of the Sino-French War and in July 1885 by the Cần Vương nationalist uprising in Annam (central Vietnam), which required the diversion of large numbers of French troops, was conducted by the Tonkin Expeditionary Corps, supported by the gunboats of the Tonkin Flotilla. The campaign officially ended in April 1886, when the expeditionary corps was reduced in size to a division of occupation, but Tonkin was not effectively pacified until 1896.

The Gin, Kinh or Jing people (Chinese: 京族, Sino-Vietnamese: Kinh tộc; Vietnamese: người Kinh tại Trung Quốc) are a community of descendants of ethnic Vietnamese people living in China. They mainly live in an area called the Jing Islands (京族三岛), off the coast of Dongxing, Fangchenggang, in the Chinese autonomous region of Guangxi. These territories were administered by the Nguyễn dynasty but were later ceded by the French to the Qing dynasty due to the 1887 convention, after the Sino-French war.

The Việt were labelled Yue (Chinese: 越族; pinyin: Yuèzú, Sino-Vietnamese: Việt tộc; Vietnamese: người Việt tại Trung Quốc) before the introduction of the names "Kinh", "Gin", or "Jing", in 1958. This name change was requested by the Kinh people, who did not want to be associated with the country of Vietnam, as 越/Yue made them look like Vietnamese citizens in China, and thus they chose their ethnic name, the Kinh.

The Retreat from Lạng Sơn (French: retraite de Lang-Son) was a controversial French strategic withdrawal in Tonkin at the end of March 1885 during the Sino-French War (August 1884 to April 1885). It represented the last major event of the conflict and was deemed a considerable embarrassment in France, further cementing negative public opinion about the colonial conflict which led to the collapse of French Prime Minister Jules Ferry's government.

Jules François Camille Ferry (French: [ʒyl fɛʁi]; 5 April 1832 – 17 March 1893) was a French statesman and republican philosopher. He was one of the leaders of the Moderate Republicans and served as Prime Minister of France from 1880 to 1881 and 1883 to 1885. He was a promoter of laicism and colonial expansion. Under the Third Republic, Ferry made primary education free and compulsory through several new laws. However, he was forced to resign following the Sino-French War in 1885 due to his unpopularity and public opinion against the war.